Multi-gigasample per second (GS/s) analog-to-digital converters (ADC) are typically used in high-speed measurement systems, multi-gigabit per second (Gbit/s) wired communication receivers, wideband wireless receivers (e.g., ultra-wideband (UWB)), and other high speed systems. Time-interleaving of ADCs can extend the overall sampling rate, but time-interleaving requires precisely spaced, multi-phase clock signals and accurate matching of ADC gain, offset and delay. Circuit techniques that increase the sampling rate of a single ADC for a given power consumption can allow a single ADC to operate in environments that previously used more complicated time-interleaving.